> For the complete documentation index, see [llms.txt](https://help.recart.com/llms.txt). Markdown versions of documentation pages are available by appending `.md` to page URLs; this page is available as [Markdown](https://help.recart.com/sms/single-vs-double-opt-in-for-sms-subscriptions.md). # Single vs. Double Opt-In for SMS Subscriptions Use this guide to choose the right opt-in method so you can build a clean, compliant SMS list while maximizing conversions. **Table of Contents** 1. [Overview](#overview) 2. [What Is Single Opt-In?](#what-is-single-optin) 3. [Risks of Single Opt-In](#risks-of-single-optin) 4. [What Is Double Opt-In?](#what-is-double-optin) 5. [Comparison: Single Opt-in vs Double Opt-in](#comparison) 6. [Why We Recommend 2FA](#why-we-recomment-2fa) 7. [How to Choose Your Opt-In Type in Recart](#how-to-choose-your-optin) 8. [FAQs](#FAQs) 9. Best Practices 10. [What's Next](#related-resources) *** ### Overview When setting up SMS marketing, one of the first choices you’ll make is how customers subscribe to your list: **single opt-in** or **double opt-in**. Both methods are compliant with TCPA and CTIA regulations, but they come with different risk levels. This guide explains the differences — and why we recommend double opt-in for most Recart merchants. ### What Is Single Opt-In? With single opt-in, customers are added to your SMS list immediately after they enter their phone number (e.g. via popup, checkout, or embedded form). No further confirmation is required. ### Risks of Single Opt-In **Pros** * Fastest signup experience * No additional user actions needed **Risks** * Anyone can enter any number — including one they don’t own * You may end up sending SMS to people who never gave consent * Can lead to compliance issues or legal risk, even if you’ve followed technical guidelines ### What Is Double Opt-In? Double opt-in adds a **verification step** to confirm that the person entering the phone number actually owns it. There are a few methods: 1. **Two-Factor Authentication (2FA)** – *Recommended* * A one-time passcode (OTP) is sent to the number * Customers verify directly on-site, without leaving the page * Cleanest and lowest-friction double opt-in option 2. **Confirmation Text Message** * Customer must reply “YES” or “CONFIRM” via SMS * Requires leaving the website to complete subscription 3. **Deep Link (SMS App Redirect)** * Customer is redirected to their Messages app to send a reply * Often causes drop-offs due to distractions ### Comparison: Single vs. Double Opt-In | Factor | Single Opt-In | Double Opt-In (2FA) | | ----------------------- | --------------------------------- | ---------------------------- | | **Signup speed** | Instant | +5–10 seconds | | **Conversion drop-off** | None | 2–8% typical | | **List quality** | Lower—may include invalid numbers | Higher—verified numbers only | | **Compliance risk** | Higher | Lower | | **Spam complaints** | More likely | Less likely | | **Recommended for** | Low-risk scenarios | Most merchants | ### Why We Recommend 2FA Using a 2FA-based double opt-in ensures that: * Your list contains only real, consented phone numbers * You protect your brand from litigation or spam complaints * You maintain high conversion rates (typically only 2–8% drop-off) This method strikes the best balance between **compliance**, **list quality**, and **user experience**. ### How to Choose Your Opt-In Type in Recart To select your SMS opt-in type in Recart: 1. Go to your **Recart dashboard** 2. Click **Opt-in Tools** 3. Select **Create New** → **Pop-up** 4. At the top of the popup builder, choose your **SMS opt-in type** from the available options: * Double Opt-in (2FA) * One-Click Opt-in * Replying “YES” as Consent ![smsoptintype](https://2167119381-files.gitbook.io/~/files/v0/b/gitbook-x-prod.appspot.com/o/spaces%2F2I45aTZ733MBi8Vps3Ib%2Fuploads%2F2I4jAhPv8hZLXBtexzb4%2Fsingle-vs-double-opt-in-for-sms-subscriptions-1.png?alt=media) Once selected, click **Continue to Editing** to finish building your popup. ### FAQs **Q: Is single opt-in illegal?** A: No — single opt-in is compliant with both TCPA and CTIA guidelines when implemented properly. However, it increases your exposure to risk and abuse. **Q: Will I lose conversions with double opt-in?** A: With 2FA-based verification, most merchants only see a 2–8% drop-off. For most, that’s a small price to pay for legal protection and higher list quality. ### Best Practices * **Recommended:** Use 2FA double opt-in for all popups to ensure list quality and compliance. * **Recommended:** If you use single opt-in, monitor spam complaints and unsubscribe rates closely. * **Recommended:** Clearly disclose what subscribers will receive before they opt in. * **Avoid:** Using single opt-in for high-volume campaigns where invalid numbers could impact deliverability. ### ### What's Next Once you've selected your opt-in type, you can: * [Build your popup](https://help.recart.com/en/articles/opt-in-tools-getting-started) and customize the design * [Review SMS compliance best practices](https://help.recart.com/en/articles/sms-compliance-and-deliverability) to stay protected * [Learn more about SMS opt-in types](https://help.recart.com/en/articles/sms-opt-in-types) for detailed setup guides This article is based on insights shared in our [blog post on SMS subscription best practices](https://blog.recart.com/single-vs-double-opt-in/). If you have any questions, reach out to - we're happy to help! --- # Agent Instructions This documentation is published with GitBook. GitBook is the documentation platform designed so that both humans and AI agents can read, navigate, and reason over technical content effectively. Learn more at gitbook.com. ## Querying This Documentation If you need additional information that is not directly available in this page, you can query the documentation dynamically by asking a question. Perform an HTTP GET request on the current page URL with the `ask` query parameter, and the optional `goal` query parameter: ``` GET https://help.recart.com/sms/single-vs-double-opt-in-for-sms-subscriptions.md?ask=&goal= ``` `ask` is the immediate question: it should be specific, self-contained, and written in natural language. `goal` is optional and describes the broader end goal you are ultimately trying to accomplish on behalf of the user. 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